This is a Caille badge motor.

There are two American rowboat motors, no connection whatsoever to each other.

(The first internal combustion American made rowboat motor EVER was called the American. No one has ever found one. There are some ads for it that indicate it was sold.)

This American is a Caille badge motor sold by the American Engine Company.

Although it is a 1915 (or later) motor, the tell is the solid skeg; it has a non folding rudder and straight tilt adjusters both of which were used on Caille's 1912-13 motors.

The ads are from 1915 Popular Science magazines.
The text block is from The Rudder, 1915, article on major manufacturers and brands of that time. It is worth reading.